Mauritania's army claims to have "completely destroyed" an Al-Qaeda camp in neighbouring Mali.
The two countries launched a joint offensive against Al-Qaeda in the Islamic Maghreb (Aqim) on 21 June but Mauritania acted alone in Friday's operation.
Four Mauritanian soldiers were wounded, two of them seriously, the army said Saturday, but it could give no figures for Aqim losses.
But the military claimed to control the area Saturday and to have destroyed three vehicles and all the tents in the camp along with their occupants. Both sides used heavy weapons, army sources told RFI.
Military sources earlier claimed that Aqim was trying to establish a new base in the Wagadou forest, where the fighting took place.
Hundreds of Malian and Mauritanian soldiers are involved in operations along Mali's western border.
Mauritania launched its first solo raid in Malian territory in September 2010, having already taken part in a joint operation with France in July.